6 
The Bulletin 
since the sulphur and phosphorus of the feed proteins constitute the 
principal sources of mineral acids in the body. The excess of mineral 
bases in the feed must be maintained at a high level. 
In practice, animals do not experience injurious effects from an excess 
of alkali as they do from an excess of acid. A needless amount of pro¬ 
tein unnecessarily taxes the acid-neutralizing capacity of the animal, 
and if carried to a sufficient extreme, results either in interference of 
the formation of bone or in its malnutrition. A high fat-content of 
milk or indigestible character of this fat when fed to individuals suf¬ 
fering from digestive disturbances causes acid intoxication by with¬ 
drawal of alkalies, by way of the feces, in the condition of difficult 
soluble calcium soaps. 
It is a known fact that poverty of the soil, or in drought, may affect 
the ash content of feeds. If the soil is poor in calcium and phosphorus, 
the crop will be correspondingly poor. Such feeds will limit the growth 
and development of bone. If a sufficient amount of vegetables, fruits, 
and milk is given, there is not likely to be an excess of mineral acids 
above the capacity of the body to neutralize. Clover and alfalfa are 
specially rich in calcium and, hence, are excellent, either as pasturage, 
cut green, or ground and fed in the mash, to make good deficiencies 
in such grains as corn. 
Aid to Construction of Tissue: Bone contains calcium in the form of 
calcium phosphate, carbonate, and fluoride. It contains magnesium 
in the form of phosphate of magnesium. Sodium chloride is also pres¬ 
ent. 
The fluids of the body contain approximately 0.85 per cent sodium 
chloride. 
Proteid bodies, feathers, and horn contain sulphur. 
The hemaglobin of the erythrocyte contains iron. The nucleus of 
the leucocyte contains phosphorus, as does also prothrombin. The 
blood also contains considerable amounts of potassium chloride, and 
sodium carbonate. Phosphates of calcium, magnesium, and sodium 
are next in abundance; the chief inorganic constituents of the cells 
being potassium phosphate. In the plasma, sodium chloride is the 
most abundant salt. 5 
In the construction of the tissues of the growing chick, calcium, 
phosphorus, potassium, sodium and chlorine play the most important 
part. 
Aid to Function: The presence of calcium salts is necessary for 
muscular contraction, and the control of both voluntary and involun¬ 
tary muscles is accompanied through the proportion of calcium, mag¬ 
nesium, sodium, and potassium salts acting upon them. Sodium salts 
6 Smith, F., A Manual of Veterinary Physiology. Third Edition. 
